178 CORAL-REEFS. 



recently elevated; and at Kamtschatka 1 there are extensive 

 tertiary beds of modern date. Evidence of the same nature, 

 but not very satisfactory, may be detected in Northern New 

 Zealand where there are two volcanoes. The co-existence 

 in other parts of the world of active volcanoes, with upraised 

 beds of a modern tertiary origin, will occur to every 

 geologist. 2 Nevertheless, until it could be shown that 

 volcanoes were inactive, or did not exist in subsiding areas, 

 the conclusion that their distribution depended on the 

 nature of the subterranean movements in progress, would 

 have been hazardous. But now, viewing the appended 

 map, it may, I think, be considered as almost established, 

 that volcanoes are often (not necessarily always) present in 

 those areas where the subterranean motive power has lately 

 forced, or is now forcing outwards the crust of the earth, 

 but that they are invariably absent in those, where the 

 surface has lately subsided or is still subsiding. 3 



On the relations of the areas of Subsidence and Elevation. 

 — The immense surfaces on the map, which, both by our 

 theory and by the plain evidence of upraised marine 

 remains, have undergone a change of level either down- 

 wards or upwards during a late period, is a most remarkable 

 fact. The existence of continents shows that the areas 



1 At Sedanka, in Lat. 58° N. (Von Buch's Descrip. des Isles 

 Canaries, p. 455). In a forthcoming part, I shall give the evidence 

 referred to with respect to the elevation of New Zealand. 



2 During the subterranean disturbances which took place in Chile, 

 in 1S35, I have shown (Geolog. Trans., 2nd Ser., vol. v. p. 606) that 

 at the same moment that a large district was upraised, volcanic matter 

 burst forth at widely separated points, through both new and old vents. 



3 We may infer from this rule, that in any old deposit, which con- 

 tains interstratified beds of erupted matter, there was at the period, and 

 in the area of its formation, a tendency to an upward movement in the 

 earth's surface, and certainly no movement of subsidence. 



